Apparatus for launch and recovery of flexible hose and method of use

ABSTRACT

An apparatus ( 130 ) for the deployment of a flexible hose having a hose coupling from an offshore platform or vessel. The apparatus comprises a support frame ( 134 ) and a rotating assembly ( 132 ) mounted on the support frame on a main rotation axis. The rotating assembly has a plurality of hose guide surfaces ( 142 ) arranged to contact a flexible hose and enable relative movement of the flexible hose with respect to the rotating assembly. The rotating assembly comprises at least one radial recess ( 139 ) disposed between a pair of adjacent hose guide surfaces, and which is configured to accommodate a hose coupling. Methods of use in riserless offshore drilling operations are described.

The present invention relates to an apparatus and method for hosedeployment, and in particular to an apparatus for launch and recovery ofa flexible hose from an offshore vessel or structure to a subsealocation, and a method of use.

BACKGROUND TO THE INVENTION

The background to the invention and its preferred embodiments will bedescribed in relation to offshore and marine operations, although itwill be appreciated that the invention also has application tofreshwater systems such as lakes and rivers.

In offshore and marine industries such as the hydrocarbon explorationand production industry, it is often necessary to use a hose totransport fluids and/or solids between a vessel or structure at surfaceand a seabed location. In this context, the hose is a flexible,collapsible conduit defining a bore through which fluids or solids maybe conveyed. Transport of the material may be upwards (i.e. from theseabed to the surface structure) or downwards (i.e. from the surfacestructure to the seabed) depending on the particular operation.

Many hoses used in such applications are required to be deployedsignificant distances. It is generally desirable to use a flexible,collapsible hose in order to reduce the cost of the hose and reduce itssize while stored on a hose storage reel. Flexible hoses used in theseapplications are formed in hose sections joined to one another by hoseconnections which are swaged onto the hose material. Such hoses havesignificant weight, particularly when combined with a weight of thematerial being transported inside the hose, and this weight may be toogreat to be supported by the inherent longitudinal strength of the hose.In these situations, it is known to support the hose with a load-bearingelement. The load-bearing element may be a nearby structural member, forexample a platform leg or riser pipe, with the hose attached to theload-bearing elements at regular intervals on the hose. An alternativeapproach is to deploy a load-bearing element in the form of the supportwire or umbilical alongside the hose, and secure the support wire to thehose at regular intervals. The support wire may be a dedicated supportwire stored on and deployed from a rail, or alternatively may be a cranewire which forms part of the standard vessel and rig deck equipment.Alternatively, an umbilical (which is a wire-sheathed, bundled cablehaving additional functionality such as supplying power and controlconduits for subsea equipment) may be used. Whatever the nature of theload-bearing element, it may be tied to the hose by means of boltedclamps, clips, chain or wire straps, rope or webbing straps.

The applicant's co-pending International Patent Publication Number WO2012/140447 relates to an apparatus and method for deployment andretrieval of the hose from an offshore structure or vessel. Theapparatus comprises a mechanism which couples a flexible hose and aflexible load-bearing element together to form a supported hose assemblyas the hose and the load-bearing elements are fed to the apparatus.

In systems such as that described in WO 2012/140447, it is necessary forthe hose to include attachment points at intervals along its length.These attachment surfaces need to be brought into close proximity withthe load-bearing element so that the hose and the load-bearing elementmay be safely and conveniently coupled to one another.

WO 2011/089479 describes a support structure for a subsea cable orsimilar element which comprises a plurality of sheaves on an assembly,and a locking mechanism which prevents rotation of the assembly duringdeployment of the cable. The locking mechanism is released to allow anintegrated element to pass the support structure.

U.S. Pat. No. 5,906,235 describes a winch for a cable, the winchcomprising an assembly of drums, The assembly is driven to rotate toenable a lump in the cable to pass around the winch.

SUMMARY OF INVENTION

It is amongst the aims and objects of the invention to provide anapparatus for the deployment of a hose and a method of use which isimproved with respect to previously proposed apparatus and methods.

It is amongst the aims and objects of the invention to provide anapparatus suitable for the deployment and recovery of a flexible hosewhich comprises hose couplings along its length and a method of use.

Another aim of the invention is to provide an apparatus suitable for thedeployment and recovery of a flexible hose which is configured to becoupled to a load-bearing element and a method of use.

Other aims and objects of the invention will become apparent from thefollowing description.

According to the first aspect of the invention, there is provided anapparatus for the deployment and recovery of a flexible hose having ahose coupling, the apparatus comprising:

-   a support frame;-   a rotating assembly mounted on the support frame on a main rotation    axis;-   wherein the rotating assembly comprises a plurality of hose guide    surfaces arranged to contact a flexible hose and enable relative    movement of the flexible hose with respect to the rotating assembly;-   and wherein the rotating assembly comprises at least one radial    recess disposed between a pair of adjacent hose guide surfaces, the    at least one radial recess configured to accommodate a hose    coupling.

The rotating assembly may comprise a plurality of arms extendingradially from the main rotation axis. The rotating assembly preferablycomprises three arms, but may comprise four or more arms.

Preferably the hose guide surfaces define an outer radius of therotating assembly.

The rotating assembly may comprise a plurality of roller assemblies, andthe roller assemblies may comprise the hose guide surfaces.

The hose guide surfaces may be located at distal ends of the arms.

Preferably, the rotating assembly is free to rotate on the main rotationaxis.

The roller assemblies may be free to rotate on respective roller axes.

The apparatus may be configured to receive a flexible hose from a hosestorage reel, and guide the flexible hose to a coupling location. Theapparatus may be configured to guide the hose to a coupling orientation,which may be a vertical coupling orientation.

The apparatus may comprise one or more lateral guides, configured toguide the hose to the hose guide surfaces of the rotating assembly. Thelateral guides may comprise one or more vertical-axis rollers.

The recess may be configured to accommodate an inflexible, stiff orrigid hose coupling, which may comprise a substantially circular crosssection, and/or may comprise a fixed outer diameter.

The hose coupling may be a connection between adjacent hose sectionsassembled together to form the hose. Alternatively, or in addition, thehose coupling may be a part of the hose configured to support the weightof the hose, for example by providing an attachment point for aload-bearing element such as a cable or umbilical.

Preferably, the recess is configured to accommodate a hose couplinghaving an outer diameter of approximately 150 mm to 250 mm, and morepreferably is configured to accommodate a hose coupling having an outerdiameter of approximately 180 mm to 205 mm.

Preferably, the recess is configured to accommodate a hose couplingcomprising a length greater than 300 mm. Preferably, the recess isconfigured to accommodate a hose coupling comprising a length ofapproximately 300 mm to 600 mm, and preferably comprises a length ofapproximately 450 mm and 500 mm.

The apparatus may comprise a stop mechanism for retaining a hose sectionwith respect to the apparatus.

According to a second aspect of the invention there is provided a systemfor deployment and recovery of a hose from an offshore structure orvessel, the system comprising a flexible hose comprising a hose couplingand the roller apparatus according to the first aspect of the invention.

The hose coupling may be an inflexible, stiff or rigid hose coupling,which may comprise a substantially circular cross section, and/or maycomprise a fixed outer diameter.

The hose coupling may be a connection between adjacent hose sectionsassembled together to form the hose. Alternatively, or in addition, thehose coupling may be a part of the hose configured to support the weightof the hose, for example by providing an attachment point for aload-bearing element such as a cable or umbilical.

Preferably, the hose coupling has an outer diameter of approximately 150mm to 250 mm, and more preferably has an outer diameter of approximately180 mm to 205 mm.

The hose coupling may comprise a length greater than 300 mm. The hosecoupling may comprise a length of approximately 300 mm to 600 mm, andpreferably comprises a length of approximately 450 mm and 500 mm.

The hose coupling preferably comprises a coupling surface for attachinga load-bearing element to the hose. The load-bearing may comprise acable or an umbilical.

Preferably the hose is a drilling fluid and/or solid return line from asubsea drilling operation.

Embodiments of the second aspect of the invention may include one ormore features of the first aspect of the invention or its embodiments,or vice versa.

According to a third aspect of the invention there is provided ariserless mud return system for an offshore drilling operation, thesystem comprising the hose deployment and recovery system of the secondaspect of the invention.

Embodiments of the third aspect of the invention may include one or morefeatures of the first or second aspects of the invention or theirembodiments, or vice versa.

According to a fourth aspect of the invention, there is provided amethod of deploying a hose from an offshore structure or vessel, themethod comprising:

-   providing an apparatus comprising a rotating assembly mounted on the    support frame on a main rotation axis and having a plurality of hose    guide surfaces;-   deploying a flexible hose having hose coupling from a hose storage    reel;-   passing the flexible hose over the hose guide surfaces and the    rotating assembly;-   accommodating a hose coupling in a radial recess disposed between a    pair of adjacent hose guide surfaces and passing the hose coupling    over the rotating assembly.

Passing the hose coupling over the rotating assembly may compriserotating the rotating assembly with respect to the main rotation axis.

The method may comprise orienting the rotating assembly to accommodatethe hose coupling.

Passing the flexible hose over the hose guide surfaces may compriserotating one or more roller assemblies of the roller apparatus.

The method may comprise freely rotating the rotating assembly on themain rotation axis, and/or may comprise freely rotating the rollerassemblies on respective roller axes.

The method may comprise guiding the flexible hose to a couplinglocation, and/or may comprise guiding the flexible hose to a couplingorientation. The coupling orientation may be a vertical couplingorientation.

The method may comprise coupling the hose to a load-bearing element,which may comprise a cable or an umbilical.

Embodiments of the fourth aspect of the invention may include one ormore features of the first to third aspects of the invention or theirembodiments, or vice versa.

According to a fifth aspect of the invention, there is provided a methodof recovering a hose to an offshore structure or vessel, the methodcomprising:

-   providing an apparatus comprising a rotating assembly mounted on the    support frame on a main rotation axis and having a plurality of hose    guide surfaces;-   recovering a flexible hose having hose coupling from a subsea    location;-   passing the flexible hose over the hose guide surfaces and the    rotating assembly;-   accommodating a hose coupling in a radial recess disposed between a    pair of adjacent hose guide surfaces and passing the hose coupling    over the rotating assembly.

The method may comprise guiding the flexible hose from a decouplingorientation and decoupling the hose from a load-bearing element. Thedecoupling orientation may be a vertical orientation.

Embodiments of the fifth aspect of the invention may include one or morefeatures of the first to fourth aspects of the invention or theirembodiments, or vice versa.

BRIEF DESCRIPTION OF THE DRAWINGS

There will now be described, by way of example only, various embodimentsof the invention with reference to the drawings, of which:

FIGS. 1A to 10 show a hose deployment system according to an embodimentof the invention, shown during sequential stages of deployment to asubsea location;

FIG. 2 is a side view of a roller apparatus according to an embodimentof the invention and used in the hose deployment system of FIGS. 1A to10;

FIGS. 3A to 3D show successive stages of deployment of a flexible hoseincluding the passing of a hose coupling over the roller apparatus ofFIG. 2; and

FIGS. 4A to 4D show successive stages of connection of flexible hosesections.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring firstly to FIGS. 1A to 10 and FIG. 2, there is shownschematically a hose deployment system 100 according to an embodiment ofthe invention, incorporating a roller apparatus 110. The system 100 isshown on an offshore drilling rig 102. The system comprises a flexiblehose 104 deployed from a hose storage reel 106, arranged to rotate abouta horizontal axis on an upper support platform 108 of a frame 110. Alower support platform 109 of the frame accommodates an umbilical 112 onan umbilical storage reel 114.

The umbilical 112 and the hose 104 are connected to a skid 118 whichsupports subsea equipment such as pumps, manifolds and subsea controlequipment.

The frame also comprises an extendable cantilever structure 116 whichprovides a guide for the hose 104 and the umbilical 112 during aninitial launch of a subsea skid 118. The cantilever structure 116provides sufficient clearance for the skid to be laterally displacedfrom the side of the frame and the offshore drilling platform 102 duringlaunch. When the skid 118 is lowered to the point at which it is clearof the side of the offshore platform, the cantilever 116 can beretracted such that the hose 104 and the umbilical extend substantiallyvertically between the upper support platform 108 and the lower supportplatform 109, through an aperture 120 provided in the lower supportplatform. As most clearly shown in FIG. 10, the hose 104 and theumbilical 112 extend vertically in close proximity to one another, toenable the hose to be clamped or otherwise attached to the umbilicalfrom the lower support platform 109. This enables the umbilical tosupport the load of the hose during deployment, during operations, andduring retrieval of the hose and subsea equipment.

The hose 104 is a flexible, collapsible hose, which is selected to berelatively low in cost and be compact when stored on a storage reel. Thehose 104 is made of a number of continuous hose sections, joinedtogether by hose couplings 122, which are in the form of rigid or stiffsub-assemblies located at respective ends of adjacent hose sections. Thehose couplings are stiff and straight and of fixed outer diameter, andare swaged onto the hose section to provide connection points betweenhose sections. The hose 104 is also required to provide engageablesurfaces for attachment of the umbilical 112 (or another load-bearingelement). These engageable surfaces are conveniently provided on thehose couplings 122 of the flexible hose.

The system 100 includes a roller apparatus 130, shown most clearly inFIG. 2, which functions to guide the hose 104 to the correct verticalposition for coupling to a load-bearing element and enable it to bedeployed over the side of the offshore drilling platform. The rollerapparatus 130 comprises a rotating assembly 132 mounted on a rollersupport frame 134. The rotating assembly 132 is free to rotate about aprimary axis of rotation 136, which extends horizontally through thesupport frame 134. The rotating assembly 132 comprises three arms 138 a,138 b and 138 c, which extend radially outwards from the primary axis ofrotation 136. Each arm 138 comprises a guide roller assembly 140, whichdefines a guide surface 142 for the hose 104 during deployment andretrieval. The roller assemblies 140 freely rotate around respectivehorizontal axes at the distal end of each arm 138.

The angular spacing between the arms 138 and the length of the armsdetermines a space 139 between an adjacent pair of guide surfaces 142.The spacing is selected to accommodate an inflexible or rigid hosecoupling 122 of the hose as will be described below. The rollerapparatus 130 also comprises a pair of vertical axis roller guides 144which laterally guide the hose 104 to the roller apparatus.

The function of the roller apparatus 130 in a hose deployment operationwill now be described with reference to FIGS. 3A to 3D. In FIG. 3A, theflexible hose 104 is shown passing through vertical roller guides 144 asit is paid out from the hose reel 106. The hose is vertically flattenedas it is deployed from the reel 106, and as it passes over the rollerapparatus 130, it is guided by the guide surfaces 142 of the rollerassemblies 140. The surface of the flexible hose 104 rolls over theindividual roller assemblies 140 without the rotating assembly 130 beingrequired to rotate about the primary axis 136.

FIG. 3B shows a hose coupling 122 of the hose 104 approaching the rollerapparatus 130. The coupling 122 defines a fixed outer diameter that islarger than the collapsible main hose, which flattens against the rollerguide surfaces 142. In this example, the hose coupling has an outerdiameter of approximately 180 mm to 205 mm, and a length ofapproximately 450 mm to 500 mm, although hose couplings of otherdimensions may be accommodated in alternative embodiments of theinvention. When the hose coupling 122 approaches the roller 130, thefreely rotating assembly 132 rotates in a clockwise or anti-clockwisedirection to position itself around the hose coupling, so that thecoupling is located in the space 139 between adjacent guide surfaces.

As the hose coupling 122 approaches the first arm 138 a of the roller, arounded shoulder 146 defined by a leading end of the coupling 122 doesnot easily pass over the roller guide surface 142. Instead, continueddeployment of the hose 104 imparts a rotating force on the rotatingassembly 132 against the guide roller, as shown in FIG. 3C. As the hosepasses through the roller apparatus, the hose coupling is accommodatedin the space 139 between an adjacent pair of roller guides until, in theposition shown in FIG. 3D, the hose coupling is released from the rollerapparatus 130 and passes substantially vertically from the upper supportplatform 108. As the hose is further deployed, it passes over the guidesurfaces 142 defined by the roller assemblies 140 until the nextcoupling 122 arrives at the roller apparatus.

The roller apparatus 130 is an effective way of guiding the hose 104 toor from a position in which it can be coupled to or decoupled from aload-bearing element such as a cable or umbilical. It offers a number ofadvantages over a sheave-type guide, such as those used with coiledtubing or flexible conveyance equipment such as wirelines. In order toaccommodate the hose couplings, a conventional sheave would require alarge radius so that the circumferential curvature is able to take thestiff hose couplings 122 without causing lifting of the hose from theguide surface and/or bending of the hose during deployment or retrieval.In an offshore environment, such a large radius sheave would have asignificant vertical height, footprint and mass, and would take up toomuch space on the platform to be practical for the envisagedapplications.

FIGS. 4A to 4D show sequential stages of the use of the support frame134 of the roller apparatus 130, during the connection of adjacent hosesections. In FIG. 4A, a first hose section 104 a has been guided throughthe roller assembly 130, and is terminated by a hose blind cap 150. Thehose blind cap 150 is secured to a support line 152 which enables thehose section to be supported from the hose reel beyond a point at whichis fully deployed from the reel. When the hose blind cap reaches theroller, a stop gate assembly 154 is closed to prevent further passage ofthe first hose section 104 a. The blind cap 150 is removed and thesupport line 152 is detached.

As shown in FIG. 4B, a second hose section 104 b is deployed from asecond hose storage reel (not shown). The second hose section 104 b isaligned with the first hose section 104 a, which is held in place by thestop gate assembly 154.

As shown in FIG. 4C, upper and lower clamping members 156 are locatedover protruding flanges 158 of respective coupling sections of the firstand second hose assemblies. A recess (not shown) in the clamping members156 accommodates the flanges 158 to form a coupling 122 which joins hosesections 104 a, 104 b.

As shown in FIG. 4D, the stop gate assembly 154 is opened to enable thecoupling 122 to pass through the vertical roller guides 144, and overthe roller apparatus 130 as described with reference to FIGS. 3A to 3D.

The invention provides a roller apparatus for the deployment of aflexible hose having a hose coupling from an offshore platform orvessel. The roller apparatus comprises a support frame and a rotatingassembly mounted on the support frame on a main rotation axis. Therotating assembly has a plurality of hose guide surfaces arranged tocontact a flexible hose and enable relative movement of the flexiblehose with respect to the rotating assembly. The rotating assemblycomprises at least one radial recess disposed between a pair of adjacenthose guide surfaces, and which is configured to accommodate a hosecoupling. Methods of use in riserless offshore drilling operations aredescribed.

Various modifications to the above-described embodiments may be madewithin the scope of the invention, and the invention extends tocombinations of features other than those expressly claimed herein.

1. An apparatus for the deployment and recovery of a flexible hosehaving a hose coupling, the apparatus comprising: a support frame; arotating assembly mounted on the support frame on a main rotation axis;wherein the rotating assembly comprises a plurality of hose guidesurfaces arranged to contact a flexible hose and enable relativemovement of the flexible hose with respect to the rotating assembly; andwherein the rotating assembly comprises at least one radial recessdisposed between a pair of adjacent hose guide surfaces, the at leastone radial recess configured to accommodate a hose coupling; and whereinthe rotating assembly is configured to freely rotate about its mainrotation axis to position itself around the hose coupling in use.
 2. Theapparatus according to claim 1, wherein the rotating assembly comprisesa plurality of arms extending radially from the main rotation axis. 3.The apparatus according to claim 1, wherein the rotating assemblycomprises a plurality of roller assemblies, and the roller assembliescomprise the hose guide surfaces.
 4. The apparatus according to claim 3,wherein the rotating assembly and the roller assemblies are free torotate on their respective axes.
 5. The apparatus according to claim 1,configured to guide the hose to a vertical coupling orientation.
 6. Theapparatus according to claim 1, wherein the recess is configured toaccommodate an inflexible, stiff or rigid hose coupling.
 7. A system fordeployment and recovery of a hose from an offshore structure or vessel,the system comprising a flexible hose comprising a hose coupling and theapparatus according to claim
 1. 8. A riserless mud return system for anoffshore drilling operation, the system comprising the hose deploymentand recovery system according to claim
 7. 9. A method of deploying ahose from an offshore structure or vessel, the method comprising:providing an apparatus comprising a rotating assembly mounted on thesupport frame on a main rotation axis and having a plurality of hoseguide surfaces; deploying a flexible hose having hose coupling from ahose storage reel; passing the flexible hose over the hose guidesurfaces and the rotating assembly; accommodating a hose coupling in aradial recess disposed between a pair of adjacent hose guide surfacesand passing the hose coupling over the rotating assembly; wherein therotating assembly freely rotates about its main rotation axis toposition itself around the hose coupling.
 10. A method of recovering ahose to an offshore structure or vessel, the method comprising:providing an apparatus comprising a rotating assembly mounted on thesupport frame on a main rotation axis and having a plurality of hoseguide surfaces; recovering a flexible hose having hose coupling from asubsea location; passing the flexible hose over the hose guide surfacesand the rotating assembly; accommodating a hose coupling in a radialrecess disposed between a pair of adjacent hose guide surfaces andpassing the hose coupling over the rotating assembly; wherein therotating assembly freely rotates about its main rotation axis toposition itself around the hose coupling.